Renix ICU/Coil Contact Refreshing

Coil ICM connectors

The contacts between the coil and the ICU on your Renix Jeep can become corroded and loose causing a complete or intermittent no-start condition. I recommend the following procedure as a maintenance precaution to insure this is eliminated as a possible cause now and in the future.

Coil ICM 2-001

The coil is attached to the ICU by two T20 Torx bolts. Remove these two bolts and lift the coil up off the ICU. You will see 2 pins and 2 sets of contacts. Clean both the pins and springy contact pieces with a good electronics cleaner and some fine sandpaper.

Squeeze the springy contacts closer together with some needlenose pliers. Apply some OxGard to the contacts. Bolt the coil back on to the ICU.

While you’re right there, unplug the connectors from the ICU and inspect the pins in the harness connector. Make sure the pins are not retracted into the connector. Spray out the connector and the receptacle of the ICU with the same good electronics cleaner you used earlier.

I feel this procedure should be performed at least once in the lifetime of a Renix Jeep.

5-11-16

12 thoughts on “Renix ICU/Coil Contact Refreshing”

  1. Would this cause it to idle low and possibly die at stop signs once the engine has reached operating temperature? It’s a 1990 xj.

  2. Is it possible to put a 91-95 engine bay wiring harness on the 87-90 fuse box? I know that all the sensors are different i just want to make sure the wires will on the bulkhead

  3. hello cruiser54… i have real enigma regardind spark.. initially i .pulled the coil wire…. to turn over engine during oil change;;; to fill oil filter. dumb…. probably cranked too many times as i flooded it … however .. no spark now..would the ecu have shut down the asd relay … is there even an asd relay on an 87 rennix?… could a 02 sensor smelling raw gas cause ecu to stop pulse. put in.new plugs… they were wet,,new coil..cleaned the coil leads and checked power there with key on…12,5 or so… also checked power to distributor end of coil wire also 12,5 or so…. but no pulse when cranking… cranks hard. checked continuity on crank sensor… seems good..cleaned grounds..cleaned harness on firewall…tried computer reset but maybe didnt reset…. disconnected battery positive…held to ground 30 seconds..reconnected..turned on key swicth..turned on headlights..turned off switch….nothing.. she was running strong before i pulled coil wire… it had to have messed up the logic… i have not unplugged cpu yet. ive heard on the early rennix the asd relay is in the pcm? where is that? there are only 4 relays by the battery. any ideas helpful… fuel pressure seems good,,
    fuel pump comes on and primes with turn of key… if there was an asd relay… would it even allow for 12.5 at the coil and power to fuel pump if defective…. no pulse! bad cpu all of the sudden? reset? maybe a short in harness but too coincidental when pulled coil wire…..

  4. also checked for pulse coming from cpu at icm connector…..cranking away…. checked using test light. no pulse. will check sync pulse coil pickup in rotor next with analog meter while cranking

    1. forget everything about an asd relay….. guess those came later. checked sync pulse coil pickup with analog voltmeter while cranking. also no problems. Here is the part i forgot ..we had cut out the rust under passenger rear and welded new plate 2 days earlier. didnt think this was an issue cause she ran fine for 2 days after. had disconnected negative battery but guess that wasn’t enough. pulling coil wire to pump oil into filter….must have aggravated the problem in the cpu after initial power shock from welding. hope i can find a good 89 or 90 cpu for a manual.

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